Over the last decades, thousands and thousands of different devices that need electrical power for their operation have been developed and produced. Many of them have been designed for mobile use, that is they have been equipped with a storage for storing electrical power such that the device is operable independent of a power supply network for at least a specified period of time. Batteries or accumulators, whether rechargeable or not, may be used for this purpose.
One of the problems that may arise with such devices is that the electrical power delivered to the device may show irregularities, for example during the startup and the shutdown process. Several non-ideal conditions may be observed when the device is switched on or off or when a battery is inserted or removed. Such conditions may for example include transients, brown-out or other oscillations of the input voltage. These conditions may have a minor impact on simple devices such as for example a mobile device for playing back music or a torch light. However, with more complex devices such as for example devices including a digital circuit like contemporary listening devices these conditions may have a negative effect on the operation of its digital circuit. They may for example cause undesired operations such as arithmetic operations of a digital processor or read/write operations of a memory block, for example an EEPROM (Electrically Erasable Programmable Read Only Memory). Such conditions may even damage the device.
To avoid these non-ideal conditions chatter-free switches may be used. However, such switches do not eliminate the above problems when the battery is inserted or removed while the ON/OFF switch remains open or closed or when there is no ON/OFF switch at all.